Slide pencil



NOV. 23, 1937. C, BQSSERT 2,099,999

f SLIDE PENCIL Filed Feb'. 18, 1936 Patented Nov. '23, 1937 UNITED STATES PATENT OFFICE Applicationv February 18, 1936, Serial No. 64,432

In Germany February 25, 1935y 7 Claims.

My invention relates to slide pencils and more especially to polypointed pencils. comprising a plurality of lead holders which are assembled lin a common case and can be shifted separately into operative position.

It is an object of my invention to provide a pencil of the kind aforesaid which is particularly simple in construction and eiiicient in use.

In the slide pencils of the kind here in question each lead holder has beenformed with aknob, the shaft of which extends through a longitudinal slot of the'V case, this knob serving to shift the holder into and out of operative position. Pencils of this kind involve the drawback that the holders yield to the pressure exerted in use on their points and recede into the case. This and other drawbacks are obviated by the present invention, by forming the slots at their ends with bayonet extensions, while each lead holder is acted upon by a separate coil spring which, when the holder is shifted into operative position with the shaft of its knob resting in the bayonet portion of the slot, causes this shaft to be applied against the wall of the bayonet slot, thereby preventing the shaft of the knob from being shifted back into the main slot.

Furthermore, the polypointed pencils hitherto known, in which the several lead holders are returned by means of pressure springs into the position where they are kept while not being used, involve certain drawbacks. The handle rods carrying the knobs and serving for displacing the lead holders into their operative position and the pressure spring are located one behind the other, in the direction of displacement, in the pencil casing wherefrom results a great wear on the coil spring due to the complete compression, i. e. the mutual contact between the wire coil windings or to a far reaching compression of the spring, when a lead holder is shifted into `operative position. A spring subjected to such wear will soon be worn out and be liable to break.

In such case, since all the lead holders depend upon the action of .a single pressure spring, the pencil will become useless altogether. Further the ,presence of a single pressure spring exerts an effect solely onto the lead holder which is advanced into operative position. If the spring is compressed under the influence of such lead holder, it has lost its influence on the other lead holders and thus is unable to maintain the same in their positions of rest. Consequently, for this purpose particular mechanisms must be inserted in the casing in order to secure the lead holders (Cl. 1Z0-14) in their position of rest; these mechanisms are not dependable for any extended length of time, but always increase the costs of the pencil. If the several mechanisms fail to work, troubles in the rest ofthe mechanisms cannot be avoided. 5 The present invention is intended to eliminate the above drawbacks.

In the drawing affixed to this specification and forming partthereof a polypointed slidepencil embodying. my invention is illustrated diagram- '10.

matically by way of example.

In the drawing.

Fig. 1 is an elevation of the slide pencil.

Fig. 2 is across section taken on the line 2--2 of Fig. 1. v 15 Fig. 3 is a cross section, partly in elevation, on lines 3-3 of Fig. 2. f

Fig. 4 is a detail of a casing according to Fig. 1.

Figs. 5 and 6 are elevations of lead holders such as shown in Fig. 1. Y

Fig. 7 shows, on a larger scale, a detail of a lead holder according to Figs. 5 and 6.

Fig. V8 is a plan View of the detail according to Fig. 7.

Referring to the drawing, the casing of a slide pencil comprises a slotted outer case I and a cap 2 screwed onto the end of case I. In the case I a thimble 4 is inserted up to anV enlargement thereof in which a plurality of inner cases 5 are secured, each of which serves for receiving a piston 6, a piston rod 1 and a pressure spring 8, and which are closed at their top ends, e. g. by means of a common disk 9 and at their bottom ends by means of bottoms I0, which form abutments for the bottom ends of the pressure springs 35 8 and which are provided with passages I I for the piston rods 1. The top ends of the pressure springs 8 exert pressure on the pistons 6 and hold the same in the position shown in Fig. 1, in which they are in contact with disk 9. 40

The Vends of the piston rods 1 protruding from the narrower cases 5 carry, on the one hand, the lead holders I2 and, on the other hand, the handle rods I 3 bent into Contact with the slotted case I and carrying knobs I6 mounted on pins 45 I4 extending through slots I5.

Fig. 3 illustrates a lead holder in its operative position, the holder being secured in position by means of a lateral extension I1 (Fig. 4) of the slots I5, which is slightly enlarged so that the pin I 4 entering the extension II is held back therein.

The slots I5 in the casing extend upwardly to the top end of the casing so that, all parts which are directly or indirectly secured to the tube 4, can be inserted in the casing together with the tube 4 whereupon the cap 2 is screwed onto the end of the casing I, thus locking the tube 4 in the casing I.

The capsule I8 inserted in the case 2 serves for storing a supply of leads and for securing in place a holder ring I9 carrying a pocket clip 20. 'I'he capsule I 8 is closed by means of a screwed cover 2|.

The pistons 6 are secured to the top end of the corresponding rod 'I for example in a manner such that the end of the piston rod is somewhat narrowed and the narrow portion is split into two portions 22, which are passed through the hole 23 in the piston and are bent at right angles, as shown in Fig. 8.

The piston rod 'I and the handle I3 may be formed integrally by stamping.

The handle rods I3 carrying the knobs I6 and Athe pressure springs 8 are located in the case I in juxtaposition. The' interior of the cases 5 may be considerably longer than the distance through Vwhich Vthe lead holders I2 are displaced plus the `length of the completely compressed pressure coil Vrod may nojt turn therein,

Various changes may be made in the details disclosed in the foregoing specification without departing frorn the invention or sacrificing the advantages thereof.

I claim:-

1. A polypointed slide pencil comprising in combination, an outer case, a plurality of inner cases, a lead holder in and extending through the bottom of each inner case, a shaft and a piston associated with each holder and a coil spring inserted between each piston and the bottom of the inner case.

2. A polypointed slide pencil comprising in combination an outer case, a plurality of inner cases in said outer case, a lead holder in each inner case, longitudinal slots formed in said outer case, a shaft xed to the bottom end of each holder and projecting through one of said slots, a piston secured to each holder and a coil spring inserted between each piston and the bottom of the inner case surrounding it, said bottom being formed with a passage for said holder.

3; The slide pencil of claim 2, in which the slots extend up to one end of said outer case.

4. The slide pencil of claim 2., in which a cap is inserted in the outer case, the parts of the lead holders carrying the pistons extending into said cap.

5. The slide pencil of claim 2, in which the bottoms of said inner cases' are formed with rectangular passages and the piston rods with a rectangular ycross-section.

6. The slideY pencil of claim 2, in which the inner length of the inner cases exceeds the cornbined lengths of the compressed spring, the piston and the distance through which the lead holder is shifted.

7. The slide pencil of claim 2, in which the piston rods extend through and are -bent outwardly into Contact with the pistons.

CHRISTIAN BOSSERT. 

